The present invention relates to a novel synergistic solid/semi solid organic composition, a process for producing such organic composition and a method of solidifying liquid neutral organic compounds using lipid modulators. Preferably, the present invention provides a method of solidification, isolation, identification and/or separation of liquid neutral organic compounds and/or mixture of organic molecules or colloids. Most preferably, the invention encompasses lipid-modulated alteration of the physical properties of vegetable oils, essential oils, mineral oils and organic solvents.
In the field of organic chemistry, many of the organic compounds are in various physical states depending on their molecular structures and the surrounding temperatures and pressure. Organic compounds are chemical compounds containing carbon atoms arranged in chains or rings, together with smaller amounts of other elements, mainly hydrogen and oxygen. These organic compounds are present either in liquid, solid or gaseous form at ambient temperature. These organic compounds may be negatively or positively charged or devoid of charge. In other words, it may have a deficiency or excess of electrons on a particular object, giving rise to a positive or negative charge, respectively. Organic compounds can be saturated or unsaturated ones. These can be vegetable oils, essential oils, mineral oils, chemical solvents, etc. Organic compounds have various physical properties such as color, odor, physical state, solubility, melting point, boiling point, freezing point etc., and alteration of one or more of such properties are required in order to make them suitable for specific industrial usage or application. In other words, modification of physical state of the organic compounds is essential/desirable for their various applications in the industry.
Organic.compounds include a group of compounds referred to as fatty acids, fatty alcohols and sterols which were originally found to be constituents of microbial, animal and vegetable fats and fatty oils. Alternatively, the fatty acids, fatty alcohols and sterols can also be synthesized chemically. The esters of fatty acids are their derivatives with alcohol.
The art is rich in use of compounds isolated from Garcinia indica for several processes as described in the following patents and publications:
Chen S, Wan M, Lok B N (1996) Planta Medica 62:381. Reddy S Y, Prabhakar JV (1994) J Am Oil Chem Soc 71:217. Sundaram B M, Gopalakrishnan C, Subramanian S, Shankaranarayan D (1983) Planta Medica 4:59. The art is also rich in proposing kokum and mahua fats as substitutes for cocoa butter for Chocolate industry (Yasuda et al. 1979, U.S. Pat. No. 4,157,405; Pairaud et al. 1982, U.S. Pat. No. 4,348,432). The art is also rich in the process of conversion of vegetable oil into fat by chemical hydrogenation (Gunstone F D, Harwood-J L, Padley F B (1994) The Lipid Handbook (2nd ed), Chapman and Hall, Madras). However, there is no description of altering the physical properties of any liquid neutral organic compounds such as vegetable oils, essential oils, mineral oils and organic solvents in a temperature-dependent manner using fatty acids or glycerol esters of fatty acids isolated from Garcinia indica. There is no report on a process of biological conversion of liquid oils to a solid or semi-solid using lipid(s) isolated from plants such as Garcinia indica. There is also no description of using free fatty acids, fatty alcohols, dicarboxylic acids (adipic, suberic, sebacic acid), cholesterol and its derivatives to solidify, isolate, identify or separate any liquid neutral organic compound in prior art. However, there are a few methods of solidifying liquid oils using fatty acyl wax esters (U.S. Pat. No. 5,763,497) and paraffin wax esters (U.S. Pat. No. 5,476,993) and hydroxyalkanoic acids (U.S. Pat. No. 5,908,377).
U.S. Pat. No. 5,476,993 discloses a process of reversibly solidifying hydrocarbons for transportation and storage. This process involves mixing hydrocarbons like crude oil with a hydrocarbon wax. The wax is melted and heated to a temperature above the solidification temperature for the mixture and mixed with the oil. The disadvantage of this process is that it employs large quantities of wax and is restricted to solidifying only crude oil that later under goes fractional distillation to separate various fractions. In addition, there is no mention of the use of hydrocarbon wax to solidify edible oils, essential oils and organic solvents.
Another U.S. Pat. No. 5,763,497, of 1998 discloses an oil-in-water type cosmetic composition comprising water, fatty acyl wax esters, and at least one of other components usable in cosmetics. However, the above method is not reversible and also involves more active components. In addition, this method has a restrictive application and not suitable for solidifying all kinds of oils and organic solvents.
Yet another U.S. Pat. No. 5,908,377 of 1999 discloses a method of solidifying liquid oils without heating the liquid oil, using a solidifying agent which includes a gel-in-oil forming material and a temporarily protective material for the gel-in-oil forming material. This method, as disclosed, has several disadvantages such as employing at least two components to prepare the solidifying agent, using hydroxystearic acids which are not suitable in food and related applications, etc. These hydroxyalkanoic long chain fatty acids are only available in minute quantities in nature and it is totally uneconomical to isolate from natural resources for any commercial use. On the other hand, these acids are very expensive to chemically synthesize them. Further, ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid) does not exhibit the solidification property. Furthermore, the above process does not envisage reversibility and is restricted to solidifying waste edible oils or waste engine oils to contain environmental pollution. In addition, the method is directed towards avoiding pollution of drains, rivers, lakes by waste edible oils and does not involve reversing the method. Moreover, this method does not result in uniform/homogenous solidification.
To over come the above problems, the present invention provides a novel synergistic solid/semi-solid organic composition comprising (a) at least one saturated long chain fatty acid and/or its glycerol esters, or at least one saturated long chain fatty alcohols, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof and (b) one or more liquid neutral organic compounds, said ingredients (a) being present in a ratio between 0.1 to 40 percent by weight and the remaining part from (b); and a process for producing the reversing synergistic solid/semi-solid composition.
The main object of the invention is to provide a novel, reversible and synergistic solidisemi-solid composition.
Another object of the invention is to provide a synergistic solid/semi-solid organic composition comprising (a) at least one saturated long chain fatty acid and/or its glycerol esters, or at least one saturated long chain fatty alcohols, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof and (b) one or more liquid neutral organic compounds.
One more object of the invention relates to a solidification of uncharged organic liquid by physical method which method is reversible.
Yet another object of the invention relates to a process for producing a novel, reversible and synergistic solid/semi-solid composition.
Still another object of the invention is to provide a reversible process for producing a novel, reversible and synergistic solid/semi-solid composition.
Our investigations to obtain insights into the mechanism of solid fat biosynthesis and accumulation in Garcinia indica, eventually led to the present invention. Table 1 represents the analysis of fatty acid composition of Triacylglycerols (TAG) obtained from mature kokum (G. indica) seeds at 120 days after flowering. The TAG contained more than 59% of stearic acid (C.sub.18:0) and 35% of oleic acid (C.sub.18:1).
The solid oil from kokum seed was mixed with various neutral liquid organic compounds and the tubes were heated to melt the fat and kept at 4 deg. C after mixing. It was observed that the liquid organic compounds were solidified. Once the organic is solidified at 4 deg. celsius it remains solid at NTP. The solidified locate can be reconverted into liquid of identical nature by simple physical process. Therefore, the present solidification process does not involve any chemical reaction. The percentage of kokum fat required for such a solidification process is given in Table 2a.
Fractionation of Kokum Fat to Identify the Solidification Principle
The lipid catalyst or the solidifying agent was purified from kokum fat using various column chromatographic procedures and C18 reverse phase High Performance Liquid Chromatography. The structure of the purified compound was elucidated.
Aliquot from the purified triacylglycerol was subjected to alkaline hydrolysis, acidified and the free fatty acids were extracted with petroleum ether [Kates M. (1964) J. Lipid Res. 5, 132-135]. The free fatty acid fraction and the water soluble deacylated fractions were used separately for solidifiing vegetable oil. In these experiments, petroleum ether fraction showed solidification property and the water-soluble deacylated fraction did not show vegetable oil solidifiing property. The hydrolyzed products were purified using HPLC (C18-reverse phase column). The purified compounds were identified as saturated fatty acids (stearic and palmitic acids). The purified saturated fatty acids were capable of solidifying liquid vegetable oils, essential oils, mineral oil and organic solvents. These experiments suggested that the free fatty acids were capable of solidifying oil.
Alternatively, free fatty acids were obtained from kokum fat by enzymatic (lipase) hydrolysis and tested for solidifying property. The free fatty acids from kokum fat showed solidifying activity.
The fatty acids obtaineom kokum fat were fractionated intomvidual fatty acids on C.sub.18 reverse phase silica thin layer chromatography. Individual fatty acids were eluted from the thin layer chromatogram plates, used for solidification activity, and found to exhibit the similar property.
The present invention describes a simple and a cost-effective method of altering physical properties of liquid neutral organic compounds by using one or more fatty acids their glycerol esters, fatty alcohols, dicarboxylic acids, sterols and mixtures thereof without involving chemical reactions.
One embodiment of the invention provides a novel synergistic solid/semi-solid organic composition, said composition comprising (a) at least one saturated long chain fatty acid and/or its glycerol ester, or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof and (b) a liquid neutral organic compound, said ingredient (a) being present in an amount between 0.1 to 40 percent by weight.
Another embodiment of the invention relates to a process for producing a novel synergistic solid/semi-solid organic composition, said process comprising mixing (a) at least one saturated long chain fatty acid and/or its glycerol ester, or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof in an amount between 0.1 to 40 percent by weight with (b) a liquid neutral organic compound. It is also possible to perform the process at varying pressures with corresponding modification in respect of other parameters of the process. The pressure can vary between 200 torr to 2500 torr.
Yet another embodiment of the invention relates to a method of solidifying liquid neutral organic compounds or their mixtures, said method comprising adding one or more fatty acids having a chain length of C.sub.10 to C.sub.31, their glycerol esters or both or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof at a concentration of 0.1 to 40% with the said liquid neutral organic compounds or their mixtures.
The preferred fatty acids employed in the present invention can be selected from decanoic acid, hendecanoic acid, aminohendecanoic acid, dodecanoic acid, aminododecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, heptacosanoic acid, octacosanoic acid, nonacosanoic acid, triacontanoic acid and hentriacontanoic acid. The preferred esters of this invention can be selected from trilaurin, trimyristin, tripalmitin, tristearin and tribehenin and mixtures thereof.
The preferred liquid neutral organic compounds used in the present invention can be selected from vegetable oils such as coconut oil, groundnut oil, olive oil, palm oil, mustard oil, sunflower oil, neem oil, cottonseed oil, rapeseed oil, soybean oil, sesame oil, corn oil, castor oil, safflower oil, rice bran oil, linseed oil, corn oil, poppy oil, fish oil, tall oil and tung oil; essential oils such as mint oil, camphor oil, cinnamon oils, citrus oil, lemon oil, orange oil, cyprus oil, eucalyptus oil, geranium oil, jasmine oil, lavender oil, lemon grass oil, rose oil, sandalwood oil, turpentine oil, clove oil, pepper oil and cardamom oil;. mineral oils such as crude fossil oil, petroleum, diesel and kerosene; and neutral organic solvents such as mono-, di- or tri-hydric alcohols, acetone, acetonitrile, aniline, benzene, butanol, n-butyl acetate, carbon disulfide, cyclohexane, diethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxan, ethanol, ethyl acetate, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monomethylether, ethyl methyl ketone, methanol, I-propanol, pyridine, toluene and xylene.
In a preferred embodiment, the process comprises taking a required part of the fatty acids or their glycerol esters or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof in an appropriate vessel with a required part of the desired liquid neutral organic compound followed by heating the mixture and mixing both the liquids thoroughly. The mixture is gradually allowed to solidify at ambient teinperature or allowed to cool and solidify at a temperature in the range of 2 deg. C to 10 deg. C or allowed to cool down at a controlled rate of 0.1 deg. C to 1 deg. C per minute to enhance thermal stability.
In another embodiment, the process comprises taking a required part of the fatty acids or their glycerol esters or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof in an appropriate vessel and heating the substance till it melts and adding such molten agent with a required part of the desired liquid neutral organic compound followed by heating the mixture and mixing both they liquids thoroughly. The mixture is gradually allowed to solidify at ambient temperature or allowed to cool and solidify at a temperature in the range of 2 deg. C to 10 deg. C or allowed to cool down at a controlled rate of 0.1 deg. C to 1 deg. C per minute to enhance thermal stability.
Preferably, the invention describes a novel process of altering the physical properties such melting and freezing points of edible oils, non edible oils, essential oils, mineral oils and organic solvents in a temperature dependent manner using fatty acids of chain length C sub. 10 to C sub. 31 and/or saturated fatty acids esters of glycerol or both or at least one saturated long chain fatty alcohol, or at least one dicarboxylic acid, or at least one sterol or mixtures thereof. One of the many advantages of this process is that it does not alter the chemical nature of the above mentioned compounds. Using this invention, the conversion of vegetable oils into higher quality vegetable fats in terms of palatability without chemical hydrogenation and the attendant trace metal contamination was achieved. With this invention, essential oils, mineral oils and organic solvents can be solidified at ambient temperatures, which have several industrial applications. The solidified oils can be used in food and feed, dairy and dairy products, cosmetics, healthcare, paints and dyes, lubricants, -petrochemical and refining, fuels, organic solvents, waxes, storing and transportation, laboratory applications, environmental protection, and several other industries.
Yet another embodiment of the invention relates to a method of solidifying oils using lipids as activators/catalysts which can find application in the manufacture of vegetable butter, margarine, ghee substitute, chocolate preparation, confectioneries, shoe polish, cosmetic lotions, lubricants, etc. It relates to a simple and economical method of obtaining solid fat without chemical hydrogenation, having physical properties that are close to those of chemically hydrogenated products. Physical properties of the lipid catalyst derived solid fats are analyzed by melting point apparatus with different percentage of lipids and the melting points of the solids so prepared were determined. One of the many advantages of the invention is that it provides a substitute process for chemical hydrogenation. Hydrogenation is a process of converting unsaturated fatty acids in liquid oils to a saturated form which in turn converts liquid oil into a solid fat useful in margarine preparation and shortening applications. The hydrogenation is an expensive process, creates undesirable trans-fatty acids, and may contain traces of metal contamination. The cost and other factors associated with chemical hydrogenation can be avoided if the vegetable oil is converted to solid fat using the lipid catalyst. To become a substitute of natural butter and chemically hydrogenated products, it must fulfill several requirements; in the first instance, its cost price should be lower than that of existing products and therefore, its method of manufacturing must be relatively simple. Secondly, the physical properties of the substitute must be comparable with other related products. Thirdly, the chemical composition of the solidified oils must be as close as possible to that of other related products or superior to the existing products. It has also been established in this invention that the chemical properties of the solidified oils remain the same such as iodine value, saponification index and fatty acid, and glyceride contents. The prepared solidified oil having low saturated fatty acids and no trans fatty acids is far superior over the hydrogenated fats and natural fats. The prepared solidified oils are especially desirable for human consumption. Common additives such as stabilizer, flavoring agent, emulsifier, anti-spattering agent, colorant, antioxidant, etc. can be added to the solidified oils of the present invention. The applicants observed that when the organic liquid is not neutral then such organic liquid does not solidify by the present method, which establishes that the present invention is restricted to solidification of uncharged liquid/solvents.
According to the present invention, the solid oils are obtained by a simple process of mixing two raw materials and the mixture is then used as such without fractionation. The products prepared in this way have physical characteristics, which are advantageous presumably because of the natural rearrangement of the various constituent molecules that were present initially.
Fatty acids (C sub. 10 to C sub. 31) and their derivatives were used as solidifying agents. Each fatty acid or fatty acid derivative was used separately and in mixture with other fatty acids/derivatives to solidify seed oils, essential oils, mineral oils and organic solvent. The minimum quantity (percent, w/w) of solidifying agent required to solidify each class of organic liquid at 25 deg. C was determined. The melting temperature of each solidified fatty acid/organic liquid mixture was determined.
It was observed that the minimum quantity (percent, w/w) of fatty acid required for the solidification of organic liquids of different classes, decreased sharply with increasing chain-length of the solidifying agent from C sub. 10 to C sub. 19 and remained more or less constant thereafter. The melting temperature of the solidified mixture increased with increasing chain length of the fatty acid that was used as solidifiing agent.
The presence of an additional carboxylic acid group at the methyl end of decanoic acid (as in sebacic acid) was found to enhance the solidification ability by more thaf ten-fold over decanoic acid. These dicarboxylic acids (C sub. 6 to C sub. 10) solidified seed oils and essential oils. However, they did not solidify mineral oils.
The ability of the agent to solidify organic liquids was enhanced by the presence of an additional hydroxyl group in the middle of the fatty acid chain. The presence of a hydroxyl group at the o-carbon (adjacent to carbonyl carbon) in C sub. 18 fatty acid was found to adversely affect the ability to solidify seed oils, as compared to stearic acid. The additional hydroxyl group in the middle of the chain was observed to play a synergistic role.
It was observed that methyl esters of hydroxystearic acids had greatly diminished solidifying abilities even though there was an intact hydroxyl group in the middle of the chain. Thus, the carbonyl hydroxyl group of the fatty acid is found to play an important role in solidification of organic liquids.
The solidifying ability of 12-hydroxystearyl alcohol was found to be nearly identical to that of 12-hydroxystearic acid (12-hydroxyoctadecanoic acid) and many fold higher than that of stearic acid. Thus, it may be proposed that two hydroxyl groups, one at the middle and the other at the end of the fatty acid chain are important factors controlling the ability of fatty acids/derivatives to solidify neutral organic liquids.
Dihydroxystearic acids with the hydroxyl groups adjacent to each other in xe2x80x98threoxe2x80x99 or xe2x80x98erythroxe2x80x99 conformation in the middle of the fatty acid chain also solidified all classes of organic liquids studied, but the same compounds showed decreased solidification ability as compared to stearic acid or 12-hydroxystearic acid. Thus, more than one hydroxyl group in the middle of the fatty acid chain was found to adversely affect the solidification ability.
The presence of an a-hydroxyl group (adjacent to the carbonyl carbon) in C sub. 20 and C sub. 22 fatty acids was found to decrease the ability of these fatty acids to solidify organic liquids. The substitution of hydrogen in the carbonyl hydroxyl with chloride decreased by five-fold, the ability of C sub. 22 fatty acid to solidify organic liquid. Thus, the carbonyl hydroxyl of the fatty acid is observed to be an important factor in the solidification of organic liquids. Since the fatty alcohol does not possess a carbonyl group, which was found to solidify all organic liquids at minimal percentages (w/w), it appears that the carbonyl (Cxe2x95x90O) group does not appear to be very important for solidification. In the case of C sub. 26 and C sub. 30 fatty acids, the replacement of hydrogen in carbonyl hydroxyl with a methyl group did not decrease the solidifying ability as compared to C sub. 26 and C sub. 30 fatty acids, suggesting that, in addition to carbonyl hydroxyl, the length of carbon chain also plays an important role in solidification.
However, it was observed that there was no significant increase in the solidification ability with very long carbon chains in the absence of a hydroxyl group as in the case of long-chain fatty acyl esters. Thus, carbonyl hydroxyl and carbon chain-length of fatty acids/derivatives were found to be important factors for solidification of organic liquids. Fatty acids and their derivatives were mixed in equal ratios by weight and used to solidify organic liquids. It was observed that there was no synergistic effect due to the mixing of the solidifiing agents.
The ability of stearic acid (solid at room temperature) to solidify fatty acids that are liquid at room temperature was studied. It was observed that the minimum quantity of stearic acid required to solidify liquid fatty acids like ethanoic acid, propanoic acid, butanoic acid, hexanoic acid, heptanoic acid, octanoic acid and nonanoic acid (C sub. 2 to C sub. 9) increased with the chain-length of the liquid fatty acid.
The rate of evaporation of volatile mineral oils and solvents was found to decrease after solidification. The rate of evapoiation was inversely proportional to the chain length of the fatty acid used for solidification.
Apart from fatty acids, it was observed that cholesterol, cholic acid and deoxycholic acid can also solidify seed oil in amounts comparable to long-chain saturated fatty acids. However, cholesteryl. oleate did not solidify seed oil even at four-fold higher concentrations.
The mechanism of the present invention may be thought of as:
a) the fatty acids by virtue of having hydrophobic and a charged hydrophilic components align themselves in a head to tail linear and perhaps perpendicular fashion to create a lattice structure with sufficient spacing for the other liquid neutral organic compounds embedded in the lattice to form a gel to solid structure.
b) alternatively, they could also form a large spherical monolayer entrapping the neutral organic compounds in the interior hydrophobic environment thus, leading to the change of liquid to solid physical form.